On my quest to build a clean G-body, I knew one of the challenges would be the engine bay. From the factory, Chevy powered cars had the alternator on the passenger side and AC compressor on the driver side. The result is a mess of hoses and wires running all over the top of the engine, not to mention a belt for each accessory.
Step 1 was stopping by a local junkyard on the hunt for a late 80’s thru early 90’s GM truck, S-10, or Astro van with a 4.3 or small block v8. My particular donor was a S-10 with 4.3 v6. I brought home everything between the radiator and the engine block, including the reverse flow water pump.
Step 2 was getting all these parts to fit on the 70’s engine. The biggest issue being the 70’s heads on my engine don’t have all the later accessory holes. The aftermarket intake also doesn’t have the extra holes and bosses that GM used to brace the setup. I ended up fabricating a bracket that ties the AC bracket to one of the water pump bolts and the front of the intake. Out of all the holes, I was only missing 1 mount hole and the bracket I fabricated secures any movement where the bolt welt. Another minor issue is that these brackets and studs from the S-10 are all threaded in metric, so some new SAE bolts where needed to fasten it to my particular engine, but keep those metric bolts for anything that needs to attach to the brackets.
Step 3 was connecting everything up to the car. For the alternator it was just a matter of getting the correct pigtail. The reverse flow water pump is practically identical to the 70’s era long pump...so is the clutch fan. Make sure you keep track of which one goes back on the car. The power steering connections depend on what year you’re dealing with and how you want to attack. If you have a 80 or newer, it should have the metric o-ring seal lines and all you have to do is connect the new pump with the stock lines or donor lines. Pre 80 cars have an inverted flare pressure line so you will either need an adaptor fitting or cut the o-ring fitting off and re-flare with an inverted flare and SAE nut on the gearbox end. Since my steering box was old and leaky, I opted for a new quick ratio box with the O-ring ports. The final item to hook up was the AC. One of the appealing features of this setup is that it kept the factory R4 style compressor. With a lot of research, I found that 88-91 F-body (camaro/firebird) use the same SAE thread AC line fittings as the G-body cars. They also have a serpentine setup similar to the trucks but with an AIR pump and possibly a little lower AC mount. I sourced a new BOP G-body condenser so it has the ports of the passenger side. The F-body liquid and suction lines connect everything together with some tweaking. If a BOP g-body liquid line is available, that would be ideal.
Some of the other features that make this system nice are that the water pump is not used to connect any brackets (except maybe the one brace), so replacing water pumps is much easier (than a Corvette serpentine drive for example.) Also the power steering pump can be upgraded to the newer style offset housing (so the fill hole isn’t at an awkward angle.) Some of these donor vehicles ran hydroboost brakes too, so you could use that pump as well if you want to ditch the vacuum booster.
The result is a much cleaner engine bay and accessories that work much better. No more power steering squeal when you turn hard lock. No more V-belts flying off due to a questionable alternator angle. Total cost was around $500 after buying new AC components and cleaning up the junk yard parts. GM performance sells a similar setup (p/n 19418818) for over $1200.
